The present disclosure relates to a recording layer for an optical information recording medium and an optical information recording medium. In particular, the present disclosure relates to a recording layer for an optical information recording medium containing a metal oxide and an optical information recording medium including the same.
Up to this time, a compact disc (CD), a digital versatile disc (DVD), and the like have served as engines of the market of optical information recording media. However, in recent years, along with development of higher definition televisions and a sharp increase in data managed by a personal computer (PC), still larger capacity optical information recording media have been desired. In order to respond to this demand, a large capacity optical information recording medium, e.g., Blu-ray Disc (registered trademark, BD), compatible with blue laser have come along, and a new market of large capacity optical information recording media is about to take off.
Recordable optical information recording media include rewritable optical information recording media typified by a compact disc-rewritable (CD-RW) and a digital-versatile disc±rewritable (DVD±RW) and write-once optical information recording media typified by a compact disc-recordable (CD-R) and a digital versatile disc-reversible (DVD-R). In particular, the latter serving as low-price media have contributed significantly to expansion of the market. Therefore, it is believed that in order to expand the market of the large capacity optical information recording media compatible with blue laser as well, reduction in price of the write-once optical information recording media is desired. In addition, it is generally said that the optical information recording medium exhibits high storage reliability because of the recording and reproduction principle as compared with a hard disc drive (HDD), a flash memory, and the like. Demands for the optical information recording media as archival media have increased in recent years and, for example, usage in storage of important information has been started.
Recoding materials used for the write-once optical information recording media include inorganic materials and organic colorant materials. The organic colorant materials have been mainly studied as the recording materials of the write-once optical information recording media in the related art. However, inorganic materials have also been studied widely as the recording materials of the large capacity optical information recording media in recent years.
As for the inorganic material studied widely, a material containing palladium oxide as one of primary components is mentioned. For example, Japanese Unexamined Patent Application Publication No. 2011-42070 proposes an inorganic recording layer containing zinc (Zn) or aluminum (Al), palladium (Pd), and oxygen (O) as primary components.